Sumire Yoshisawa is a fat, long, red-haired, red-eyed girl. She used to compete in gymnastics, but due to a leg injury, she started coaching others. She is a kind and reserved person but can come off as shy and awkward and is easily flustered. Sumire has a big appetite, but her injury caused a stop of physical activity, and her metabolism slowed rapidly, causing her to get fat. She is unaware of her weight gain and believes she has an unhealthy diet and should adopt her diet.